Can crushing device



March 20, 1962 Filed June l5, 1959 R. T. BEACH 3,025,837

CAN CRUSHING DEvcE 4 Sheets-Sheet l @E ff INVENTOR. Fezze/f T fqc.

March 20, 1962 Filed June l5, 1959 R. T. BEACH CAN CRUSHING DEVl'CE 4Sheets-Sheet 2 INVENToR. 42 FEA/eff TEeac/.

March 20, 1962 R. T. BEACH CAN CRUSHING DEVICE 4 Sheets-Sheet 3 FiledJune l5, 1959 R. T. BEACH CAN CRUSI-IING DEVICE March 20, 1962 4Sheets-Sheet 4 Filed June l5, 19,59

3,025,337 CAN CRUSHRNG DEVICE Reuben T. Beach, Royal Oak, Mich.,assigner to Joseph C. Beach, Mount Clements, Mich. Filed Iune 15, 1959,Ser. No. 820,185 7 Claims. (Cl. 121-38) This invention relates to animproved can crushing device which is adapted to crush or compress,after they have been emptied, metal cans of the type in which food, oil,etc., are sold. This invention is an improvement over that shown in mycopending application Serial No. 560,705 tiled January 23, 1956, for CanCrushing Device, and now abandoned.

As explained in said copending application, the problem of disposing ofcans becomes more and more acute as the use ot this type of packagingbecomes more and more common and the costs of transporting and otherwisedumping such used cans increases.

It is an object of this invention to provide a new and improved can'crushing device.

Another object of this invention is to provide such a crushing devicewhich is inexpensive to manufacture, trouble free in operation and whichwill satisfactorily crush the cans.

Another object is to provide such a can crushing device in which eithera compressed gas or a liquid under pressure may be used as theenergizing medium.

A further object is to provide such a crushing device in which themoveable element or piston is smoothly driven in the crushing directionand which will have a very rapid return stroke.

A further object is to provide an improved valve and valve actuatingmechanism in which a single actuator may be moved in a rst direction tolock the valve in a rst position and in a second direction to unlock thevalve for movement to a second position.

Another object is to provide a still different type of valve in whichthe valve is pressure actuated into the piston return position.

A still further object is to provide a new trip device for operating acan ejecting mechanism..

Other objects will be apparent from the specification, claims and thedrawings in which:

FIG. l is a view in front elevation showing a can crushing deviceembodying the invention;

FIG. 2 is a top plan view of the device of FIG. l;

FIG. 3 is a bottom plan view of the device of FIG. l;

FIG. 4 is a side view in elevation of the device of FIG. l with certainparts shown in section;

FIG. 5 is an enlarged view lof a portion of the device showing one ofthe valving elements;

FIG. 6 is an enlarged view of a portion of the device showing theactuating device for the power fluid control valve;

FIG. 7 is an enlarged sectional view of the power uid control valve ofFIG. 6;

FiG. 8 is a partial view taken substantially along the line 8-3 of FIG.4 looking in the direction of the arrows;

FIG. 9 is a bottom plan view of the crushing device showing a modiiiedform of control valve;

FIG. l0 is a sectional view of the form of device shown in FIG. 8showing a modified form of power valve and the modified actuatortherefor;

FIG. ll is a View similar to FIG. 9 but showing the power valve actuatorin another position; and,

FIG. l2 is a partial view showing the modied form of the upper end ofthe valve actuating rod.

Referring to the drawings by characters of reference the numeral 1designates generally a can crushing device having an outer sheetmaterial shell providing a front wall 2, a rear wall d, and side walls 6and 8. The upper 3,025,837 Patented Mar. 20, 1962 portion of the frontwall 2 is provided with an aperture or opening through which the cans tobe crushed are inserted between the moveable crushing head 10 and afixed upper head 12. The front opening is closable by a door 14 hingedas at 16 and latchable in closed position by a latch 18 having a handle2t) which is rotatable to actuate a bolt 22 which serves to latch thedoor closed and also to engage an actuating rod 24 which when depressedby this bolt 22 actuates the power iluid controlling valve 26 foradmitting fluid (gas or liquid) from the fluid source connected byconduit 2S to the valve inlet 30 in a manner to be described below.

The device 1 is provided with a plate member 32 located adjacent theopen bottom wall of the device 1. The rectangular upper head l2 isrigidly secured to the rectangular bottom wall member 32 by corner rods34. The crushing head 1l) includes a substantially rectangular plate 33secured to a ring 35 as by studs 37. The ring 35 is in turn rigidlysecured to the upper end of a moveable tubular member 36 as by weldingwhereby the plate 33 forms a head for the member 36. The member 36telescopes over a second tubular member 38 which is secured to thebottom plate member 32 as by the ring 40 and studs 42. As shown members36 and 38 are secured to the respective rings 35 and 45 by welding d4,but it will be appreciated that other ways of fastening the rings to thecylindrical members may be used. It will also be appreciated that thejoints between the member 38, ring 4b, and bottom plate member 32 aswell as between plate 33, ring 35 and member 36 must be fluid tight andif desired a gasket could, of course, be used.

The upper end of the inner tubular member 38 is closed by an annularhead d6 which has an upper portion 48 with an outer diametersubstantially tting the inner diameter of the outer tubular member 36and a lower portion 5t) of smaller diameter which ts within and issuitably secured in iluid tight relation to the upper end of the innertubular member 38. The upper portion 48 is circumferentially recessed toreceive an O-ring 52 which prevents fluid iiow between the cylindermember 36 and head 46.

A fluid conveying tube 54 extends longitudinally of the cylinder member38 and has its upper end portion suitably secured in iluid tightrelation within the central aperture 55 of the annular head 46. The tube54 communicatively connects an expansible chamber 56 located between theplate 33 and head 46 with a chamber 63 formed within the inner tube 38.It will be apparent that as fluid under pressure is supplied through thetube 54 into the chamber 56 that the head lll and attached outer tubularmember 36 will move upward to cause the head 10 to move toward the head12 and, if the fluid is of suiiicient pressure, crush a can placedbetween the heads lil and 12.

The lower end of the tube 54 terminates a short distance above thebottom plate member 32 and is normally partially closed by an upwardlyfacing cup-shaped valving element 58. The element 5S has its cylindricalupwardly opening side wall 60 telescopically fitting the lower end ofthe tube 54 and its centrally apertured bottom wall 62 normally held inengagement with the lower end of the tube 54 by a spring 64 whichpreferably is of the helical conical shaped type whereby it will takethe least possible longitudinal space when fully collapsed. This, aswill be evident, permits the tube 54 to terminate nearer the member 32and a reduced length to the tubing 38 since a greater proportion of theuid in the chamber 68 may be utilized for movement of the element 58.The wall 60 of the element 58 is provided with a plurality of apertures66, four being shown, which when the element 5S is in the full lineposition (FIGS. 4 and 5) are closed by the wall of the element 58 andiluid flow therethrough is prevented. This leaves the central aperture69 in the end wall 62 as the only means of communication between thetube 54 and the chamber 68 (formed within the cylindrical member 38intermediate the lower plate member 32 and the head 46). When however,the v-alving member 58 is in its lower position (shown in dot-dash linein FIG. the apertures 66 are open and Afluid may flow therethroughbetween the tube 54 and chamber 68. As will be subsequently explainedthe valving element 58 is normally held in its up position by the spring64 and is moved to its lower position by the pressure of the fluidexhausting from the chamber 56 through tube 54 into chamber 68, as thehead 10 is pulled downwardly toward the head 46 by springs 70 connectedbetween the upper head 12 and the bottom plate member 32 (see FIG. 3).

Fluid is suppiled to and exhausted from the chamber 68 through a tube 72which extends longitudinally through the chamber 68 with its upper endterminating just below the head 46 and its lower end portion extendingthrough an aperture in the plate member 32 and communicating with a port74 of the power fluid valve 26 (see FIGS. 4 and 6). The valve 26 isprovided with an exhaust port 76 for exhausting fluid from the chamber68 via the tube 72.

The body of the valve 26 is provided with a pair of substantiallyparallel cylindrical passageways 78 and 80 having one end portionthereof joined together by a connecting passageway 82. The passageway 78into which the inlet 38 opens is of lesser diameter than that of thepassageway 80 into which the port 76 opens for a purpose which willsubsequently be made clear.

Intermediate the port 38 and the passageway 82 the passageway 78 isprovided with a valve seat 84 which is controlled by a cylindrical valvemember 86 which slidably ts the passageway 78. The lower end of themember 86 may carry a resilient seat 88 if desired and upwardly fromthis seat 88 it may be provided with a first circumferential groove 90and still further upwardly it may be provided with a secondcircumferential groove 92 which receives an O-ring 94 which cooperateswith the passageway to provide a seal to prevent uid now outwardly ofthe passageway 78.

Intermediate the port 76 and the passageway 82, the passageway 80 isprovided with a valve seat 96 which is controlled by a cylindrical valvemember 98 which slidably fits the passageway 80. The lower end of themember 98 may carry a resilient seat 100, if desired, which iscooperable with the seat 96 to prevent fluid flow therethrough. Ifdesired the member 98 could be provided with 1ari O-ring to preventfluid ow outwardly of the open end of chamber 80.

A walking beam 102 is pivotally secured to the valve body as by a bolt104. One end of the beam 102 is slotted to receive a pin 184 carried bythe valve member 86 and the other end is likewise slotted to receive apin 106 carried by the valve member 98. 'Ihe beam 102 is -resilientlyurged into either of its two rotated positions (see FIG. 7) by means ofa detent mechanism 108 comprising a spring urged plunger 110 and aV-shaped projection 112 on the beam 102. As will be understood from astudy of FIG. 7, movement of the beam in a clockwise direction moves themember 98 downwardly to close the port 96 to prevent uid flow outwardlyof the port 76 and moves the member 86 upwardly to open the port 84whereby fluid under pressure from the conduit 28 may flow through thepassageway 82 into the lower end of the passageway 80 which is in opencommunication with the port 74 (full line position of FIG. 7).

In this position inlet pressure acts on the full area of the member 86urging it upwardly and on the area of the member 98 located within theseat 96. Fluid will pass through the valve '26 until the pressure in thechamber 56 and port 76 increase sufficiently whereby the force exertedon the member 98 overcomes the force exerted on the member 86 plus theforce exerted by the detent mechanism 108. When this occurs the member98 moves upwardly to open the port 96 and the member 86 moves downwardlyto close the port 84. It will be noted that as the member 98 moves awayfrom the port 96 the pressure below the member 98 acts on an enlargedarea of the member and exerts an increased force to insure a positivevalve movement. Before the member 88 opens the exhaust port 76 thedetent mechanism will have passed overcenter and the force thereof whichwas opposing this movement of the valve now aids this movement and arapid snap-action from fluid admitting to fluid exhausting positions ofvalve 26 will occur.

The valve 26 is `actuated to its fluid admitting position by a bellcrank lever 114 fulcrumed on a pin 116 carried on a U-shaped bracket 118secured to the upper surface of bottom plate member 32 (see FIG. 7). Thebracket is external of the cylindrical members 36 and 38. One arm 120 ofthe lever 114 has its camming surface 122 engaged by the actuating rod24 which upon actuation rotates the lever 114 in a counterclockwisedirection causing the camming surface 124 of its other arm 126 `toengage the cam receiving surface 128 of the valve 26 to urge the valveinto liuid admitting position. The arm 126 it will be observed extendsdownwardly through `an aperture 138` in the bottom member 32. The valve26 will be held in this fluid admitting position by the detent mechanism108.

The crushing head 10 is much like the member 9 of my aforesaid copendingapplication Serial No. 560,705 and includes a hinged platform 132comprising rod like members 134 which cooperate with alternately spacedrods 136 on vthe under side of the upper head 12 to reduce the pressurerequired to crush the cans as described in said copending application.The chief difference between the construction shown herein and that ofthe copending application is in the latch 138. The latch 138 comprises awedge shaped element 140 secured to an elongated spring element 142 asby drive screws 144. The spring element 142 resiliently holds the latch138 within an aperture 146 in the wall 6. As the head 10 is movedupwardly, the adjacent portion `of the platform 32 moves upwardly pastthe camming edge 148 of the wedge element 140 camming the elementoutwardly against the force of the spring element 142. At the upper endof the stroke of the head 10, the platform 132 will have passed beyondthe upwardly facing shoulder 150 so that when the head 10 returns to itsoriginal position the platform 132 will rotate counterclockwise aboutits hinge point (FIG. 4) and the crushed can will slide through theaperture 152 in the rear wall 4 and through chute 154 secured to thewall 4.

In operation, the handle 20 is turned to unlatch the door 14 which isthen opened and a can to be crushed is placed with one end on the head10. The door 14 is then closed and the latch 18 turned so that the bolt22 locks the door 14. This movement of the bolt 22 also causes it toengage the rod 24 and move it downwardly thus rotating the `bell cranklever 114 to actuate the valve 26 to fluid admitting position asdescribed above. Fluid then flows from the conduit 28 through the valve26 and tube 72 into the chamber 68. With the cylindrical members 36 and38 in the position shown in FIG. 4 the chamber 68 is normally lled witha liquid substantially to the top end of the tube 72. As the fluid,normally air under pressure, is admitted through the tube 72 into thespace in chamber 68 above the liquid, the liquid is forced upwardlythrough the aperture 69 of the valvingelement 58 through the tube 54into the chamber 56 forcing the head `10 upwardly in a can crushingdirection. The rate at which liquid flows from chamber 68 into thechamber 56 is restricted yby the size of the aperture 69 and the upwardmovement of the head 10 is rendered fairly independent of the crushingforce and a smooth and positive upward movement is achieved. Shortly thecan begins to collapse and as it collapses more and more, the pressurein the chamber 56 will increase as well as that in the passageway 8Gbelow the lower end of the Valve member 98. When the can is compressedas much as desired, the pressure in passageway 80 will increase to thepoint where the valve 26 will be actuated into its fluid exhaustingposition as described above. The incoming fluid (air) is stopped and theair above the liquid level in chamber 68 starts to exhaust through thetube 72 and exhaust port 76.

The tension springs 70 help to return the head 10 and cylindrical member36 to its downward position forcing the liquid from chamber 56 throughtube 54 into charnber 68. The differential in pressure across thevalving element 58 causes it to move downwardly against the force of thespring 64 and open the apertures 66 for increasing the rate of liquidreturn to the chamber 68. I have yfound that this action of element 58is highly desirable since the restricted liquid flow is highly desirablefor proper movement in the can crushing direction with a rapid returnstroke which is accomplished by the open ports in the valve element 58.

In FIGS. 9, 10, and 1l there is shown a modified form of the valveactuating mechanism and a diierent form of valve 226 much like the valveshown in said copending application. In the construction shown in saidcopending application the bell crank lever is held in its valve actuatedposition by a pin which engages a shoulder on the bell crank lever andwhich pin holds the lever in its actuated position until it is movedaway from the shoulder by the upward movement of the crusher. Thismechanism utilizes two rods. The mechanism shown herein comprises singlerod 224 which is similar to rod 24 and which engages one arm 220 of abell crank lever 214 pivoted on pin 216 and which has an arm 226engageable with the valve actuator 200 of the valve 226. The lever 214is held in its actuated position by a shoulder 312 of a second lever 314pivotedly mounted on pin 316. The lever 314 has an arm 320 having a camsurface 322 resiliently held against an upwardly facing shoulder 323 onthe rod 224 by a spring 324 connected between the lever arms 320 and220. With the lever 314 its position as shown in FIG. 10 the shoulder312 is engageable with a shoulder 212 on the lever 214 to hold the leverin its counterclockwise actuated position to hold valve 226 open againstthe force of spring 227 to permit iuid to ow to the chamber 68.

The lever 314 may however be rotated clockwise by means of the upwardmovement of the rod 224 to move the shoulder 312 out of engagement withthe shoulder 212 of lever 214 thereby permitting the spring 227 of thevalve 226 to move the valve 226 to uid exhausting position. The rod 224unlike the rod 24 has a portion extending upwardly beyond the bolt 22and terminates in an upper lip 229 lying in the path of movement of thehead 10. Downward movement of the rod 224 to open the valve 226 isaccomplished in much the same manner as described above upon movement ofthe bolt 22 into latching positions. In this form the bolt 22 engages anupwardly facing shoulder 231 of the rod 224. As the lever 214 is rotatedcounterclockwise, the resilient action of the spring 324 permits thelever 314 to cam about the cam surface 315 to move relative to the lever214. When the cam surfaceV 212 moves beyond the cam surface 312, thespring 324 pulls the levers 214 and 314 into the relative positionsshown in FIG. l to lock the lever 214 in a position to hold the valve226 open to supply air to the chamber 68.

When the can is crushed and the -head reaches the upper end of itsstroke, the head 10 engages the lip 229 and moves the rod 224 upwardlyto rotate the lever 314 until the surface 312 no longer engages thesurface 212 at which time the lever 214 is released and the spring 227will return the valve 226 to its position in which air from the supplyconduit 228 is terminated and air from the chamber 68 exhausts throughthe exhaust conduit 231. The relative positions of the levers 214 `and314 and valve 226 will then be as in FIG. 11. As in the preferred formthe upward movement of the rod 224 also resets the latch 18 to itsinitial position.

In order to insure that the door 14 cannot be opened during a cancrushing operation, a latch mechanism 400 is provided. This mechanism isspring urged into door locking position but is held in unlocked positionby the head 10 when it is in its fully down position. This issubstantially the same arrangement as is disclosed and claimed in thesaid copending application.

What is claimed and is desired to be secured by United States LettersPatent is as follows:

1. In a can crusher, a pair of cylindrical members adapted to telescopeone within the other, first and second end members closing opposite endsof the inside one of said members and forming an interior chambertherein, a first tube extending through said first end member into saidinterior chamber and terminating within an upper portion of saidchamber, a third member closing one end of the outside one of saidcylindrical members, said third end member and said outer cylindricalmember being cooperable with said second end member to form a secondchamber which is expansible and collapsible upon relative movement ofsaid cylindrical members, said interior chamber being of greater volumethan the maximum volume of said second chamber, said second end memberhaving an aperture therethrough, a second tube sealed within saidaperture and extending into said interior chamber and terminating in alower portion of said inner member, and asymmetric ow means cooperablewith said second tube to control the rate of flow of uid between saidchambers.

2. In a can Crusher, a pair of `cylindrical members adapted to telescopeone within the other, first and second end members closing the ends ofthe inside one of said members and forming an interior chamber therein,a rst tube extending through said rst end member into said interiorchamber and terminating within an upper portion of said chamber, a thirdmember closing one end of the outside one of said cylindrical members,said third end member and said outer cylindrical member being cooperablewith said second end member to form a second chamber which is expansibleand collapsible upon relative movement of said cylindrical members, saidvolurne of said interior chamber being greater than the maximum volumeof said second chamber, said second end member having an aperturetherethrough, a second tube seaied within said aperture and extendinginto said interior chamber and terminating in a lower portion of saidinner member, a check valve member cooperable with said second tube andeiective to provide a greater impedance to the ow of fluid in adirection out of said interior chamber into said expansible collapsiblechamber than in the reverse direction.

3. In a can crusher, a pair of cylindrical members adapted to telescopeone within the other, first and second end members closing the ends ofthe inside one of said members and forming an interior chamber therein,a rst tube extending through said iirst end member into said interiorchamber and terminating adjacent an upper portion of said chamber, athird member closing one end of the outside one of said cylindricalmembers, said third end member and said outer cylindrical member beingcooperable with said second end member to form a chamber which isexpansible and collapsible upon relative movement of said cylindricalmembers, said second end member having an aperture therethrough, asecond tube sealed within said aperture and extending into said interiorchamber and terminating in a lower portion of said inner member, a cupshaped valve member having an end wall and an upwardly extending sidewall telescopically fitting the outward end portion of said second tube,means providing a iiuid ow passageway through said Valve which is openedand closed upon movement of said valve member, said end wall of saidvalve member being provided with an aperture therethrough to form a uidiiow passageway past said valve member, and means normally maintainingsaid valve member in a position to restrict iiuid iiow through saidapertures in said second tube.

'-lA In a can Crusher, a pair of cylindrical members adapted totelescope one within the other, irst and second end members closing theends of the inside one of Vsaid members and forming an interior chambertherein, a first tube extending through said first end member into saidinterior chamber and terminating adjacent an upper portion of saidchamber, a third member closing one end of the outside one of saidcylindrical members, said third end member and said outer cylindricalmember being cooperable with said second end member to form a chamberwhich is expansible and collapsible upon relative movement of saidcylindrical members, said second end member having an aperturetherethrough, a second tube sealed within said aperture and extendinginto said interior chamber and terminating in a lower portion of saidinner member, a cup shaped valve member having an end wall and anupwardly extending side wall telescopi-cally tting the outward endportion of said second tube, said side wall being provided withapertures which are opened and closed upon movement of said valvemember, said end wall of said valve member being provided with an`aperture therethrough to form a fluid flow passageway past said valvemember, `and resilient means normally maintaining said valve member in aposition to restrict fiuid flow through said apertures in said secondtube.

5. In a can crusher, a pair of cylindrical members adapted to telescopeone within the other, first and second end members closing the ends ofthe inside one of said members and forming an interior chamber therein,a first tube extending through said rst end member into saidinteriorchamber and terminating adjacent an upper portion of said chamber, athird member closing one end of the outside one of said cylindricalmembers, said third end member and said outer cylindrical member beingcooperable with sa'id second end member to form a chamber which isexpansible and collapsible upon relative movement of said cylindricalmembers, said second end member having an aperture therethrough, asecond tube sealed within said Vaperture and extending into saidinterior chamber and terminating in a lower portion of said innermember, a cup shaped valve member having an end wall and an 'upwardlyextending side wall telescopically fitting the outward end portion ofsaid second tube, means providing a iiuid flow passageway through saidvalve which is opened and closed upon movement of said valve member,said end wall of said valve member being Vprovided with an aperturetherethrough to form a iiuid ow passageway past said Valve member, and ahelically coiled conically shaped spring interposed between said endwall of said valve member and said first end member Yfor normallymaintaining said valve member in a position to restrict iiuid 4flowthrough said apertures in said 'second tube. Y

6. In a can Crusher, a pair of cylindrical members adapted to telescopeone within the other, iirst and second .end members closing the ends ofthe inside one of said "members and lforming an interior chambertherein, a irst tube extending through `said first end member into saidinterior chamber and terminating adjacent an upper portionof saidchamber, a third member closing one end ofthe outside one of saidcylindrical members, said third end member and said outer cylindricalmember being cooperable with said second end member to form a chamberwhich is expansible and collapsible upon relative movement of saidcylindrical members, said second end member having an aperturetherethrough, a second tube sealed within said aperture and extendinginto said interior chamber and terminating in a lower portion of saidinner member, a cup shaped valve member having an end wall and anupwardly extending side wall telescopically tting the outward endportion of said second tube, said side wall being provided withapertures which are opened and closed upon movement of said valvemember, said end wall of said valve member being provided with anaperture therethrough to form a fluid flow passageway past said valvemember, said end wall of said valve member being concave outwardly andprovided with a central aperture therethrough, said concave end wallhaving an outturned flange around the periphery of said centralaperture, and a helically coiled conically shaped spring having itslarger diameter seating against said first end member and its smallerdiameter substantially equal to and telescoping about said outturnedange.

7. In a can crusher, a pair of spaced plate-like members, means ixedlysecured to said members at spaced peripheral locations for holding saidmembers against relative movement, a first hollow cylinder having oneend portion thereof secured in uid tight relation to a first of saidspaced members with its other end portion extending toward butterminating short of the other of said spaced members, a first endmember closing said other end portion of said iirst cylinder, a secondhollow cylinder adapted to telescope over vsaid iirst cylinder, a secondend member closing a first end portion of said second cylinder whichextends toward said other spaced member, said first end member having aperipheral portion outwardly of said first cylinder, said peripheralportion being provided with a peripheral aperture, an 'O-ring in saidaperture and engaging the inner surface of said second cylinder toprovidel a tiuid tight joint, said first end member being provided withan aperture therethrough, a rst tube having one end portion sealedwithin said aperture and its other end portion extending toward saidfirst spaced member, a cup-shaped valve member having an end wall and acylindrical side wall, said side wall telescopically fitting over saidother end portion of said tubesaid end wall of said valve member havingan aperture therethrough, said side wall of said valve member beingprovided with at least one aperture which is opened and closed uponmovement of said valve member relative to said tube, a spring positionedbetween said end wall of said valve member and said first spaced memberand resiliently urging said valve member toward said tube whereby .fluidflow through said apertures is restricted, said first spaced memberhaving an aperture therethrough, a second tube having one end portionsealed to said first spaced member and closing its said aperture, saidsecond tube extending through the hollow interior of said first cylinderand having its other end portion terminating adjacent said 'first endmember, a valve member carried by said first spaced member externally ofsaid first cylin der and overlying said aperture in said irstspacedmember and controlling fluid fiow through said second tube, said valvemember having a first operative position to permit tiuid to liow intoand a second position to permit fluid exhaust from said first cylinderthrough said second tube, a liquid Vin Vsaid first cylinder, means foractuating said valve member into its said first operative positionwhereby uid under -pressure may be admitted into said iirst cylinder andpropel said liquid through said irst tube intoan-expansible-contractable chamber formed by said first and second endmembers and said second cylinder, to cause said second end member tomove toward said other spaced member, and means rendered eiective inresponse to iiuid pressure in one of said cylinders for actuating saidvalve into its said second position, and spring means resiliently urgingsaid second cylinder in a direction to contract saidexhaustible-contractable chamber.

References 'Cited in the file of this patent UNITED STATES PATENTS739,566 Riddell May 9, 1905 tra.; ...vm

